docs: def has_vtable(decl_type):
      """True, if class has virtual table, False otherwise"""
      assert isinstance(decl_type, class_declaration.class_t)
      return bool(
          decl_type.calldefs(
              lambda f: isinstance(f, calldef_members.member_function_t) and
              f.virtuality != calldef_types.VIRTUALITY_TYPES.NOT_VIRTUAL,
              recursive=False,
              allow_empty=True))